Sewer pipe



Dec. 1, 1931.

. H. cuiaRlE SEWER PIPE i-"iled Aug. 2', 1929 Qa" (e. LLM, .Sm I

Patented Dec. 1, 1931 'y IIN-iranA STATES PfarriazNr oFFicE i v CLARE H. CUR/RIE, OF WEBSTER CITY, IOWA, ASSIGNOR, BY MESNE ASSIGNMENTS; T

L. E. ARMSTRONG REALTY, & INVESTMENT C70., OF FORT DODGE, IOWA, A CORPORA- k TIoN or Iowav SEWER PIPE Application vfiled. August 2, 1929. Serial No. 383,005.l

continuous and of concrete moulded in forms erected in the trench or excavation.

For sewage'conveying, however, it is essential to protect or cover the surface of concrete pipe lines from the destructive and cor-' rosive action of the acid constituents of the sewage being handled, and therefore it is common practice'to line the inner surface of` concrete pipe with a non-corrosive material,

20 such as vitrilied clay. v

nthe present disclosure thislining has the forni of thin segmental plates called liners, and the purpose of vt-he invention is to provide an improved method for anchoring the liners to the surrounding concrete body of the pipe, vand further to provide a method of construction for pipe lines which will vinsure the sealing of the yinner lining to the passage of gases to the concrete and otherwise lend itself to the erection of continuous poured concrete pipe lines as distinguished from pre-cast pipe sections, although the latter isA also contemplated.

A preferred embodiment of my invention is disclosed in the accompanying drawings,

in which Figure lis a view in `cross section of a sewer pipe constructed in accordance with my invention; Y

Figure 2 is a view in longitudinal section through the pipe as taken on line 2 2 of Figure l; Y I

' Figure 3 is a perspective viewof a single liner,andk

Figure 4 is an enlarged detail view in cross' section ofthe pipe at one of the lugs, showing the several forms that may be used.

As clearly shown in Figure l, the pipe is cylindric' in shape and of the required diameter and thickness, and consisting of an o ute'r layer or V,shell 1 of concrete and an inner layervor lining ofvitrified clay 2, made up of a multitude of pre-cast segments or curvilinear` plates 3 joined with each other by lap joints at their four edges. The concrete outer shellis 'considerably thicker than the inner lining, in fact, they thickness of the lining is not a vital factor as kits function is primarily` that of a protective'y coating lfor the inside of the pipe.

1 Each liner or segmental plate is rectangulaiiin'shape, either square or elongated in one direction,las desired, but curved on an arc of a circle corresponding to the internaldiameter of the pipe. As shown in Figure 3, each liner'is slightly longer in the direction of the pipe, and at one end (left) there is an offset flange or lip 3a similar to the bellshaped flange at the end of the ordinary precast sewer pipe. The opposite end of the liner is plain, a joint or overlap being made with the forward end of an adjacent plate having the same lip 3a, the lap occurring on the outside `of the pipe so that the inner surface is perfectly smooth.

The side edges of each plate are cast to provide square shoulders 3b, 3b of a depth one#y half the thickness of the liner and a width about twice the thickness. 1 These shoulders, A

longitudinal joints between the liners of one circular course fall between the joints of the courses on either side, as in Figure 2.

And, finally, each liner has one or more holes i cored through it along the longitudinal center line. As shown (Figure 3, there are two of such holes provided, one being spaced inwardly from each end about onefourth the length of the liner. On the inner face of the liner these holes are counter-sunk.

These liners are moulded or cast of clay and then fired in the same manner that pipe and other vitriiied products are made, so that their exterior surfaces present the same hard glazed finish common to such products.

The preferred method of -constructing. a pipe line, incorporating the liners, will be understood from the following: Two cylin-4 dric forms A and B of suitable length wouldbe used, one for the inside and lthe yother for the outside, with the space between to be iilled with concrete, after the inner lining has been constructed around the inner form A. This would be done by erecting the inner form and then building up the lining around the form liner by liner. As the liners are put in place, however, lugs or pins 5 are inserted through the holes 4 from the inside of the liners. These lugs have the shape of pins or bolts with a flat conical head at one end of a round shank, and are preferably made of some noncorrosive metal such as Monel metal (a nickel alloy) or other suitable material. The holes in the liners are sized to receive the lugs with a snug fit, the heads seating flush in the counter-sunk recesses on the inner faces of the liners and the shank extending through and ybeyond the outer surfaces thereof, to be eventually embedded in the concrete outer shell or layer. A Y

Consequently, the length of the lugs is gov-V erned by the distance they should'eXtend into the concrete to provide a iirm anchorage, and, if desired, notches 5a may be formed along the shank, as shown in Figure 4,'to increase the holding capacity of these lugs. Other modifications in the lugs will be later noted.

Having erected the lining about the inner form with the lugs in place, the entire outer surface of the lining 2 is then coated or sprayed with a sealing compound, such as asphaltum, tar' or other suitable substance which is not eHected by the destructive acid gases in the sewage. This coating serves not only to fill in and seal the joints and crevices between liners and between the lugs and the holes, but provides an intermediate protective layer 6 between the inner lining and the outer -body of concrete.

The lining having thus been erected and sealed, the outer form B is then placed around the inner form and the concrete poured in the usual manner and allowed to set and harden. The forms, which would be of sectional design, are then removed and the same operation repeated for the next section of the pipe.

The pipe so constructed would thus have an inner lining of vitrified clay, an intermediate layer of sealing compound, and an outer shell or layer of concrete in which are firmly embedded the ends of the lugs which anchor the lining to the concrete structure of the pipe.

One of the chief advantages of this method of construction is the use of the separate lugs inserted through cored holes in the liners, as compared vfor instance, with ribs, beads, grooves or other anchoring devices cast on Vthe outer face of the liners for the purpose of afording an anchoragein the concrete. Inthe manufacturel of the `liners,the ease of drawing them from the moulds `deternmnes Vthe shape and arrangement of these integral anchoring devices. As a result, an anchoring projection which is suitable from a manufacturing standpoint is not generally practical in the construction of the sewer pipe, on account. of the difficulty in vobtaining a perfect anchorage in the concrete, due to the fact that in pouring the concrete it does not fill in completely around the projections, but leaves pockets or voids which Lweakens the pipe structure, this being particularly true where the projections extend longitudinally of the liners. lith the use Vof the separate lugs, however, it is only necessary to core holes through the plates, thereby materially simplifying the manufacture of the lining material. Again, the lugs may be made of a material more suitable for anchoring purposes than that of the liner itself, such as metal, and their-shape is such that the concrete readily flows between and around them so that they lbecome irmlyembedded. Moreover,

separate anchoring members permits of variation in theirlength and shape, to. meet different operating conditions. For instance, the shanks .of the lugs may be lengthened to extend through the concrete shell, with their projecting ends 5b threaded to receive locking members orthreaded extensions provided at both ends, as shown indotted lines (Figure a), and which can be used for supporting the forms if the contractor desires.

Having'set forth a preferred embodiment of my invention,

I claim: l. sewer pipe comprising an outer cyhndrlc shell of relatively thick concrete, a thin layer .of a non-corrosive sealing comn poiuid covering the inner surface of said shell,

an inner lining consisting of thin plates of avitreous substance joined edge to edge, and anchor members consisting of pins of noncorrosive material passing through holes in said plates with their shank portions embedded radially in said outer shell.

2. A sewer pipe comprising an outer cylindric shell of relatively thick concrete, a thin layer of a non-.corrosive sealing; compound covering the inner surface of said shell, an inner vitreous lining of relatively thin plates adapted to be laid edge to edge and having holes therethrough, and anchoring members consisting of pins of a non-corrosive metal adapted to be inserted through the holes in said plates from the inside of the pipe and tei' shank portions embedded in said outer s el Signed at Webster City, Iowa, this23rd day of July, 1929. Y

CLARE H. CURRIE. 

